Kinetics of enthalpy relaxation of milk protein concentrate powder upon ageing and its effect on solubility

► Milk protein concentrate (MPC) shows a distinct pattern of enthalpy relaxation. ► Enthalpy recovery is rapid for first 48 h followed by a slower steady increase. ► Enthalpy value increases with higher water activity and longer storage period. ► Enthalpy value was much higher for samples with moisture content ⩾ 8%. ► Similar timescale of solubility loss and enthalpy relaxation of MPC upon storage.